fernald: sphecidae from argentine. 269 



Legs dark reddish brown to black. Fore metatarsi witli eleven comb teeth more 

 than half the length of the segment, the first one shorter. Inner contour of hind 

 tibia straight. Otherwise the legs have no differential characters. 



Length, 29 mm. Expanse of wings, 44 mm. 



Described from one female specimen captured at Cordova, Argentine. 



This species in some regards seems to resemble Chlorion fuliginosum, C. ser- 

 villei, and C. nitidiventris, but comparison with specimens of the first two species 

 shows numerous differences, and the description of the third fails to agree with it 

 in a number of points. 



I take great pleasure in naming this species for Prof. W. M. Davis of Harvard 

 University. 



Sphex nigrocinctus, sp. nov. 



Female. Head almost all black ; thorax, median segment, first segment of petiole, 

 coxae, and trochanters entirely black. The other segments of the legs, and the 

 abdomen, except the fourth segment, red. Wings hyaline, with a faint yellowish 

 shade near the base ; slightly fuliginous along the outer margin. 



Head large, quite quadrate from above, the cheeks being quite broad at the top 

 and the frons but little hollowed between the eyes. From in front the outline is 

 nearly circular. Clypeus and frons rather sparsely golden pubescent almost to the 

 ocelli and with quite numerous long yellow hairs. Anterior margin of the clypeus 

 with its middle third straight, transverse, and with a small tooth at each end of this 

 portion where the margin bends upward, just above which is a small, noticeable red 

 spot. Centre of the clypeus somewhat arched ; but a rounded triangular area from 

 the highest point of this to the margin is flattened. Frontal suture from the an- 

 tennae to the anterior ocellus well developed, and this region is without pubescence. 

 Ocellar area well marked by depressed lines. Immediately behind it is an elevated 

 transverse-oval area a little wider than the ocellar area. The portions of the frons, 

 vertex, and occiput not pubescent are black sericeous, which on the cheeks close 

 behind the eyes, and covering the whole of the cheeks lower down, becomes golden 

 sericeous. Cheeks wide above, narrowing quickly below the level of the neck, and 

 giving a long wedge-shaped piece, when viewed from the side, the surface above 

 bearing a few scattered, long yellow hairs. Lateral ocelli nearer each other than 

 to the eyes. Inner margins of the eyes parallel. Antennae black, black sericeous, 

 the scape reddish beneath except at its tip, glistening, and with a very few short 

 black hairs. Relative lengths of filament segments 1/31, 2/19, 3/20, 4/19. Mandi- 

 bles stout, each reaching but little beyond the base of the other, the terminal tooth 

 and inner margin black as far toward the base as the inner side of a well-developed 

 lateral tooth ; the remainder red, with scattered aciculations and a fringe of quite 

 long red hairs on the posterior face. 



Thorax black ; the dorsal edge of the collar, mesonotum, scutellum, postscutel- 

 lum, middle of the dorsum of the median segment, front of the tegulae, prothoracic 

 lobes, a large triangular area extending backward from the lower part of the 

 episternal groove of the mesopleuron toward the mesocoxae, a large spot on each 

 side of the petiole on the end of the median segment, and a strip along the side of 



